Abstract:Objective To evaluate the clinical feasibility of underwater endoscopic resection by double nylon endoloop combination with high-frequency electric snare for the treatment of thick-pedunculated colorectal polyps.Methods In our study, 43 patients with colorectal polyps with thick stalk underwent underwater endoscopic resection of double endoloop combination with high-frequency electric snare were included from January 2017 to June 2018. Resected tumor size, procedure time, en-bloc resection rate and complication rate were collected and analyzed.Results The median tumor size (cm) was 2.7 cm (1.0~3.5 cm), pedicle average diameter(cm) was 0.9 cm (0.5~1.5 cm); The procedure time (min) was 9.2 min (5~16 min). The total volume of water was 330 mL (120~750 mL). The number of nylon rope ligation times was 1.1 times (1~2 times). The success rate of nylon rope was 95.4% (41/43). The success rate of nylon rope was 100.0%. The complete resection rate was 100.0%, the en-bloc resection rate was 100.0%. 43 polyps confirmed adenomatous by pathological examination. None of the patients had bleeding in the operation. No delayed bleeding occurred during follow-up.Conclusion Underwater endoscopic resection of colorectal polyps with thick stalk by double nylon endoloop combination with high-frequency electric snare has a short procedure time and low complication rate. So it is an effective and feasible therapy for colorectal polyps with thick stalk.